Effect of nitrobenzene and gibberellic acid on growth, yield and economic returns of late-sown lentil (Lens culinaris L.)

Abstract

Plant Growth Regulators (PGRs) mitigate yield losses in late-sown lentils (Lens culinaris L.) by enhancing nutrient uptake and photosynthetic efficiency. A field experiment was conducted during the Rabi season of 2024-25 to evaluate the effects of different PGRs on growth, yield and economic performance of late sown lentil. The experiment utilized a Randomized Complete Block Design with five treatments and four dispersed replications. Treatments were T₁: Flora (20% nitrobenzene) @ 2 ml L^-1 sprayed twice (35 and 50 DAS), T₂: Flora @ 2 ml L^-1 sprayed once (50 DAS), T₃: GA₃ @ 0.2 g L^-1 sprayed twice (25 and 50 DAS), T₄: GA₃ @ 0.2 g L^-1 sprayed once (50 DAS) and T₅: control. Results indicated that PGR application significantly enhanced the growth, yield and yield contributing characters. The highest seed yield (1.94 t ha^-1) was obtained from T₁ due to the highest number of pods plant^-1 (50.6), while the lowest yield (1.43 t ha^-1) was achieved in control (T₅). Treatment T₁ providing a 35.7% yield increase over the control. T₁ also exhibited the maximum value of harvest index (63.8%) and the most profitable, obtaining the highest gross return (BDT 180,100 ha^-1), gross margin (BDT 100,300 ha^-1), and benefit–cost ratio (2.26). Results suggest that two foliar applications of 20% nitrobenzene @ 2 ml L^-1 (at 35 and 50 DAS) are more effective than gibberellic acid for maximizing the yield and profitability of late-sown lentil.

Bangladesh J. Agril. Res. 51(1): 489-499, March 2026